Olivier Giroud scored a stunning winner as a much-changed Arsenal side saw off 10-man Red Star Belgrade in their Europa League clash.

Arsene Wenger made nine alterations from the team that lost at Watford on Saturday and it was an underwhelming display from his men until Giroud's overhead kick settled the game.

The 1-0 win maintains Arsenal's perfect start to their Europa League campaign as they move closer to qualifying for the round of 32.

Red Star hit the post in the first half and worked Petr Cech, and the hosts were incensed to lose Milan Rodic to a red card in the closing stages.

Despite making a host of changes, Wenger's experienced campaigners showed their class, Cech making a number of key saves before Theo Walcott, Jack Wilshere and Giroud combined for the only goal of the contest.

It was a slow start for both sides but Red Star goalkeeper Milan Borjan did superbly to keep out Walcott's effort on 15 minutes, saving with his feet from the England international.

Red Star skipper Mitchell Donald arrowed a shot wide of Cech's goal with the hosts' first opening of the game.

Striker Richmond Boakye, reportedly attracting the attention of Chelsea, headed against the post when free in front of goal as Arsenal failed to deal with Nenad Krsticic's corner.

The visitors seemed rattled and Reiss Nelson allowed Nemanja Radonjic to collect the ball from a cross, forcing a low save from Cech, before Nelson recovered to block Radonjic's second attempt off the rebound.

Arsenal should have taken the lead soon after the interval.

Teenager Joe Willock did well to break into the box and feed Walcott, whose drilled strike flew towards Giroud, with the Frenchman prodding at the ball when unmarked seven yards from goal.

Nelson was next to make in-roads but his pass to Walcott saw the forward mis-kick altogether, the young wing-back then stinging the palms of Borjan with his own strike.

Red Star almost made Arsenal pay for their profligacy as Krsticic sent a bullet header goalwards but too close to Cech to beat the Gunners captain.

Mohamed Elneny then gifted possession to Radonijc and he too forced Cech into action with a well-struck effort.

With neither side able to find a breakthrough, Red Star were reduced to 10 men when Rodic was shown a second yellow card with just under 10 minutes remaining for catching Francis Coquelin with a stray arm.

It took Arsenal hardly any time to make their numerical advantage pay off as Wilshere and Walcott exchanged passes before the latter headed the ball across for Giroud to finish in spectacular style and secure the win.